Manufacture of dry-sealing envelopes



l June-2o, 1939. v. E. HEYWOQD. f 2,163,038

nmunc'rum: oF DRY-sEAL1NG ENvELoPEs Filed Aug. 15, 193s 3 Sheets-Sheet l June 20, 1939. v. E. HEYwooD -2,153,038

IANUFACTURE 0F DRY-.SEALING ENVELOPES Fild Aug. 13, 1955 3 Sheets-Sheet 2 i mw June 20, 1939. v. E. HEYwooD IANUFACTURE OF DRY-SEALING ENVELOPES Filed Aug. 13, 1936 3 Sheets-Sheet 5 172 Gaz/5f:

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Patented June 20, 1939 UNITED STATES PATENTv OFFICE MANUFACTURE oF DRY-SEALING ENvELoPEs Vincent E. Heywood, Worcester, Mass., assigner to United States Envelope Company, Springfield, Mass., a corporation of Maine Application August 13, 1936, Serial No. 95,871

16 Claims.-

'I'he present invention relates to methods of and apparatus for the manufacture of envelopesv of the so-called dry-sealing type, being envelopes adapted to be adhesively sealed without need for any wetting or moistening of adhesiverial, and this property being availed of to obtain the sealing of the envelope merely by the act of pressing the two coated areas into contact with each other.

Such a dry-sealing envelope, of a structure 0 which normally maintains its two cooperating adhesive areas out of contact, and protected from exposure and dirt, is shown and described by Vogel Patent No. 1,944,020, January 16, 1934. For illustrative purposes, I have shown my invention as applied to the manufacture of this patented Vogel envelope,-but it will be understood that such showing is merely by way of example, and that my invention is not limited to the production of any particular type or style of dry-sealing envelope, except as may be specied in the appended claims. v

My invention is particularly concerned with the method and the means employed for pro- /ducing on each envelope, or on the blank therefor,` its two cooperating dry-adhesive-coated areas,-su'ch means and method of my invention involving radical departures from previous practices in the manufacture of dry-sealing envelopes. Other and further objects and advantages of the invention will be made apparent in blank-warping instrumentalities provided by the mechanism of Fig. 2.

Figs. 6 and 7 are large scale fragmentary views illustrating the application of' the dry-sealing adhesive to successive blanks.

Fig. 8 is a large scale fragmentary view illustrating a modification of the means employed for applying the dry-sealing adhesive;

Fig.l 9 is a schematic or diagrammatic View, illustrating by successive stages or steps marked a, b, c, etc., the sequence of the operations performed on the envelope blanks in the manufacture of the envelopes, according to my invention.

Like reference characters refer to like parts in the different figures.

Referring rst to Figs. 1, la and 1b, the portion vI of the blank provides the envelopes front wall, while the rear wall is provided by the overlapping adhesive attachment of blank portion 2 to infolded side flaps 3, 3. 'I'he upper extremity of folded portion 2 is left free and unsecured, to provide a ap 4 adjacent to the seal flap 5. With both flaps 4 and 5 folded down as shown, their respective coatings 6 and 1 of dry-sealing adhesive are on the inside, and thus fully protected from exposure and from accidental contact with each other in the packing vand handling of the envelope. In the use of said envelope, the seal ilap 5 is rst lifted, giving access to the pocket for the insertion of an inclosure; then, after flap 4 has been turned up and over through approximately to expose its coated area 6, the Sealing of the envelope is effected by simply pressing down the closure ap 5 to contact its coated area I with the coated area 6, in the absence of any need for moistening either of said areas.

Heretofore, al' complicated and protracted procedure has been in use for the manufacture of dry-sealing envelopes of this type, whereinit will be noted the coated areas 6 and 1 must be on opposite surfaces of the blank or sheet from which the envelope is made. This circumstance, coupled with the fact that the usual coating materials (latex or rubber-cement solutions) are diiiicult to apply to paper by the use of ordinary gumming dies, gumming rollers, and the like, had made it expedient, in the application Iof these coating liquids, to virtually flow the same in a continuous lm onto the areas to be coated,this mode of treatment having given rise to the practice (see Winkler et al. Patent No. 2,019,946, November 5, 1935) of so shingling or stepping 'a succession of the flat blanks (Fig. 1D) as to expose in the movement of the shingled blank assembly past the open mouth of a receptacle containing such coating liquid only the limited area of each blank which it is desired to coat with such solution, the latter thus being spread in a substantially continuous lmto cover only the successive blank areas so exposed (for example, only the flap areas 1, 1 of a succession of the shingled flat blanks of Fig. lb).

, According to the aforesaid patented Winkler et al. procedure, `the so-coated blanks are maintained in shingled or stepped relation while advancing progressively through a drying cham.- ber,-the prolonged travel through such chamber procuring the evaporation of the liquid from said so-coated areas 1, 1; then, with the blanks still maintained in such shingled relation, the entire operation (coating and prolonged drying) has to be repeated for the exposed flap areas 6, 6 on the reverse or opposite side of the travelling shingled assembly of flat blanks. That is to say, in the aforesaid patented Winkler et al. mechanism, each at blank is rst coated on one edge 1 with the liquid dry-sealing substance, and then subjected to a prolonged drying period for the evaporation of the liquid; next, the other Aedge 6 must be similarly coated, following which a second prolonged period for drying and evaporation is necessary. Not until the blank is fully dried after its second application of the coating liquid can it be delivered to the creasing, folding and gluing instrumentalities which convert it into the envelope structure shown by Fig. l.

My copending companion application Serial No. 70,619, filed March 24, 1936, deals, among other things, with the production in each blank, prior to any application of the coating liquid thereto, of a transverse fold which disposes ad- 'jacent to each other the two blank areas (4 and 5, Fig. lb) to be coated; in this way, upon shingling of the so-folded blanks to expose on each blank only the said two adjacent areas, the latter can be coated by a single application of the coating liquid, instead of by the two applications required in the aforesaid lWinkler et al. procedure; furthermore, the time required for drying the liquid coating is practically only onehalf the time required in said Winkler et al. machine, because of my improved method, the two coated areas of each blank can be dried simultaneously.

The present invention utilizes the transverse folding of each blank, prior to coating same, which is characteristic of the procedure of my aforesaid copending application,-but the present invention procures the application of the coating liquid to the`so-foided blanks in the entire absence of any shingling or stepping of thel latter, thereby greatly simplifying the process of manufacture and the machinery therefor. An organization of mechanism for carrying out my improved method of manufacture in the absence of such shingling or stepping is shown in Fig. 2, and the same will now be described in detail, with reference to the schematic showing of Fig. 9, which depicts the successive stages of the process.

Referring to Fig. 2, the machine framework 8 supports an inclined plate 9, whereon is -received between suitable posts I0, I a stack or pile of the blanks (Fig. lb) with their inside faces uppermost, and in the relative position indicated at a, Fig. 9. The lowermost blank of the stack bridges a transverse opening II of plate 9, through which opening projects, into substantially tangential relation to said lowermost blank,

a portionv of the periphery of a clockwise rotating roller I2. The surface of roller I2 provides a suction opening I3 elongated in the direction of said rollers axis, or transversely to said lowermost blank, said opening I3 communicating with a suitable interior passage I4 which, by the rotation of roller I2, is alternately connected to and disconnected from a source of vacuum, by any suitable valve, not shown.

Said valve, as opening I3 approaches the lowermost blank, produces suction through said opening to seize transversely the back portion 2 of said blank and to draw it through opening II of plate 9,--this seizure and movement by roller I2, in conjunction with an adjacent roller I5 over which the blank portion I is drawn, producing, (see b, Fig. 9), a transverse line of fold I6 between said blank portions I and,2. This folding results in disposing right next to each other those surfaces of the seal ap 5 and the marginal portion 4 which are to receive the liquid coating,-being surfaces which, except for such folding, would be on opposite sides of the blank. Consequently, each blank as thus transversely folded, is in condition to receive a single application of the coating liquid for the two areas thereof .to be coated, said two areas having been brought into juxtaposition so that they constitute, in effect, only a single area. But the drying of a lm of dry-adhesive substance on such a two-part area is apt to cause difficulty, from the tendency of the two parts to stick together; consequently, the same as in my aforesaid copending application, I preferably make provision here for avoiding such difficulty by preliminarily imparting to the margin 4 of each blank, before it is withdrawn from the stack, a definite tendency to curl or spring away from the ap 5 which, by the aforesaid transverse folding, is

disposed adjacent to said margin 4; in this way,.

despite the application of the coating liquid simultaneously to the two parts of the single area, the separation of said two parts, prior to drying of said solution, is insured. To this end, in the 'arrangement of mechanism shown by Fig. 2,

` each blank before its withdrawal from the stack `is acted upon as follows:-

Referring to Figs. 3, 4 and 5, the margin 4 ofthe lowermost blank, over-hanging the lower edge of plate 9, is seized and pulled down by an oscillatory hollow suction arm I1, here shown as pivoted on the shaft of roller I2. This operation carries the margin 4 into the path of a blade I8, carried by an oscillatory swinging arm I8; in the movement of arm I9 from the position of Fig. 4 to the position of Fig. 5. the blade IB strips the margin 4 from the suction device I1 and bends it, as shown in Fig. 5, under a companion blade 20 carried by an arm 2I. Thereupon, arm

2| moves toward the arm t9, causing'the blade 20 to free the margin 4 from the blade I8 and producing a definite downward curl 2| of said margin (see position b; Fig.. 9.) All of this takes place on the lowermost blank of the stack just before such blank is seized, as above described, by suction roller I2, whose opening I3 takes hold of blank portion 2 and carriesvthe latter upwardly until the buckle or bend is entered between said roller I2Aand the other roller' I45,mak ing the aforesaid fold I6; the curl 2I so formed in margin 4 is only temporarily flattened out by its passage between the rollers I2 and I5.

According to my invention, the thus pre-curled and pre-folded blanksas delivered successively by the rollers I2 and I5 are adapted to be stacked provided to engage each blank from the rear, as

tertically, one above the other,-as here shown in such a manner as to face downwardly the surfaces destined to receive the liquid adhesive coating (i. e., the adjacent exposed surfaces of blank portions 4 and 5). To this end, as shown in Fig. 2, I provide in advance of rollers i2 and i a suitable pile-forming and retaining mechanism for operation on the folded blanks successively projected outwardly, fold I 6 foremost, from said rollers; this mechanism, as here shown, consists of a suitable vertical receptacle, whose crosssectional shape, as dened by a front portion 22 and rear portion 23, and opposite lateral portions, not shown, corresponds substantially to the contour of the partly-folded blank bodies. The front and rear portions 22 and 23 and the side portions, not shown` of said receptacle may be either in the form of walls or in the form of vertical rods to engage and guide the edges of the folded blanks in their descent toward the receptacle bottom. The front wall portion at its upper end is extended to provide stops 22 to arrest each blank by engagement with its fold i6; suitable joggers or pushers 24 are preferably it is projected by the rollers I2 and I5, so as to insure its proper alinement with the confining and guiding surfaces of the verticai receptacle.

As delivered to the top of said receptacle, each partly folded blank is received and supported be'- tween the open convolutions of a slowly-rotating spiral 25,-the blank being gradually lowered into the receptacle by the rotation of said spiral, and a stack or pile of such blanks gradually building up in said receptacle, one above the other, until the receptacle is filled. The stack or pile is supportedv in the vertical receptacle by inturned lips 26, 26 on the front and rear portions 22, 23'and also by a pair of belts 21 (only one being shown) that underlie the extended side flaps 3, 3 of the lowermost partly-folded blank; additional support is afforded by the underlying upwardly opening mouth 28 of a receptacle or tub 29, containing the liquid coating solution in suicient quantity to maintain it level in the mouth 28 with the top edge of said mouth; however, the liquid does not spill over said top edge, owing to the constant pressure maintained on the overlying pile of blanks by'the rotating spiral 25. The mouth 28 is elongated transversely to correspond in length substantially to the lengthv of the blank margin 4 which directly overlies said mouth, as shown in Fig. 6, and also at c, Fig. 9; thus, as each lowermost blank is withdrawn from the bottom of the vertical receptacle by movement to the right, Fig. 2, past said receptacles front portion 22, the margin 4 and also the adjacent flap portion 5 of said blank receive a coating of the Vadhesive solution, by being drawn across the open mouth 28 which is kept lled with such solution to its upper edge.

Such withdrawal movement is here shown, (see Figs. 6 and '1), as effected by a rotary hollow segmental member 38, the peripheral portions of which provide suitable suction openings 3| which engage and seize the underlying port'on' 2 of each lowermost blank. to pull down the fold I6 past the ledge or lip 26 of front portion 22, thus freeing the blank from the vertical receptacle and transferring its support to the upper courses of the travelling belts 21. The peripheral gaps in segment 3U`prevent any contact of the latter with the freshly'coated surfaces 6 and 1 of the blank portions 4 and 5, respectively, I have discovered that any tendency of the coating solution to seize between successive blank withldrawals can be overcome by keeping the mouth 28 in motion, relative to the lowermost blank of the vertical pile, and for this purpose, as shown in Fig. 2, the tub or receptacle 29 is mounted for sliding or reciprocatory movement on a rod 32, the motion being imparted by a rocking lever 33 actuated by a rotating cam 34. By this'motion, the mouth 28 is made to travel to the right with the blank that is being withdrawn by the suction segment 30, but the tub motion is at a very much slower speed; the mouth 28 reverses its motion and starts to travel tothe left before the flap portion 5 of the blank is fully parted from the mouth. Referring to Fig. 7this left hand motion, owing to the adhesion between the marginal portion 4 and the rubber lip 35 ofl mouth 28, produces a buckle 35 in the folded blank, which pro'- motes the downward spring of fold I6 from the forward retaining ledge 26, thereby greatly assisting the action of the suction segment 3!! in freeing the blank from the vertical pile. Thus the motion of mouth 28 not only acts to prevent any seizing by the coating solution, but also insures an accurately-timed separation and withdrawal of the lowermos't partly-folded blank,

from the vertical pile.

The freshly coated blank thus transferred t0 the travelling belts 21, with its coated surfaces 6 and 1 facing downwardly, is conveyed flatwise on said belts'to the right, Fig. 2, (see d, Fig. 9) beneath a set of rollers 31 which engage the side aps 3, 3 above the belts and thus prevent slippage of the conveyed blanks. Each blank so conveyed is delivered into one of the-open compartments 38 of an endless drier chain 39, theA travel of the latter being so coordinated with the operation of suction segments 39 and belts 21 that a drier compartment 38 arrives in blank receiving position at the proper time to receive each individual blank so separated and conveyed. The endless drier 39, which maybe carried to any desired height, thus handles the coated partly-folded blanks individually, said blanks as received by said drier being carried by the travel vof said drier first upwardly and then downwardly, and at the end of their downward travel being .individually withdrawn from the drier and subjected to folding operations, as hereinafter described, for manufacture into envelopes such as shown by Fig. 1'.

In the drier 39, each compartment of -which receives an individual blank, the upward blank travel occurs with the coated surfaces 4 and 5 facing downwardly, but this condition is reversed on the downwardy moving side of the drienwhere the coated surfaces 4 and 5 face upwardly (see e, Fig. 9). By the time each blank arrives at the lower end of the downwardly moving side of the.

drier 39, the treated surfaces 4 and 5 of said blank will have dried suilciently for the blank to be -freely handled,the evaporation of the liquid from the coating being'promoted, if desired, `by inclosing the drier 39 in a suitable heating chamber, notshown. Thus the manufacture of each dry-adhesive coated blankfarriving at the discharge end of drier 39 in the partly-folded condition shown at e, Fig. 9, can be prceedcd with, by the employment of any suitable mechanism for converting such "blank, by appropriate creasing, gluing, and folding instrumentalities, into the envelope shown by Fig. 1. In Fig. 2, I have shown one way of so operating on the delivered blank (see e, Fig. 9) as to convert it intothe envelope of Fig. l; but my invention is not in any sense limited to this way of converting, or to the mechanism shown; the latter is merely illustrative.

As shown in Fig. 2, a suitable take-off drum 40 provides an elongate suction opening 4| which, in the clockwise rotation of said drum, will engage and seize the under or uncoated side of the projecting iiap portion 5 of each blank as it arrives at the lower end of drier 39. The action of drum draws the doubled or folded blank out of the drier toward a blade 42, the inner edge of which is` contacted by the inside surface of portion 2 and margin 4 so that, as drum 40 pulls the blank downwardly onto a belt 42 that partly encircles said drum, the previously-folded back portion 2 is unfolded (see j, Fig. 9) ,-and in this condition the blank, after release of the suction of opening 4| at or near the point where the belt 43 leaves the drum 4U, is delivered to a pair of rollers 44, 44, which project it flatwise and outside face uppermost (see g, Fig. 9) onto a suitable set of gage table belts 45, where it comes to rest against suitable stops or gages 46.

In this condition, the extended blank is centered and squared against the gages 46 by the action of the belts and, if need be, by the action of a revolving brush 41, the blank being prevented from buckling by suitable overhead rails or skids 48. In this position, the margin 4 of the blank overlies a clockwise rotating cylinder ,49, the periphery of which provides a suitable gripper 50,* extending longitudinally of said cylinder and with which cooperates a suitable tucker blade 5| carried by a rotary arm 52 above the blank. The blade 5| in its counterclockwise rotation engages the coated margin 4 and tucks or folds it into said gripperl 50, forming thereby (see h, Fig. 9) the crease 53 (Fig. 1a) which disposes the coated area 6 on the inside of flap 4. 'I'he gripper 50, .by the rotation of cylinder 49, carries the blank around (see z', Fig. 9) and delivers it, inside surface uppermost, onto folding station belts 54,-the usual means, not shown, being employed to effect the release of crease or fold 53 by gripper 50 as the belts 54 are engaged. In this travel around cylinder 49, the extended side flaps 3, 3 of the blank are preferably coated with" ordinary wet glue, by means of a pair of suitable gluing rollers 55 (only one being shown) which receive the glue from a transfer roller 56, running in a suitable receptacle 51.

On the belts 54, each extended blank, inside surface uppermost, (see i, Fig. 9), and with'its side flaps 3, 3 wet with glue on the underside, is conveyed, fold 53 foremost, to folding instrumentalities of substantially the construction and mode of operation shown by Novick Patent No. 1,298,776, April 1, 1919, for the Yfolding up and over of said side flaps 3, 3 and for the refolding, on line I6, of back portion 2 so that the latter will overlap and adhere to the glue-coated surfaces of the inturned side flaps. A detailed showing and description of said folding instrumentalities is unnecessary, since the same per se form no part of the present invention.

It is suilcient to note that such folding mechanism includes a pair of centering stops or gages 58, 58 (only one being shown), which are en-k gaged by the reentrant angle portions 59, 59 of each blank received and conveyed on the belts 54,- this engagement serving to brin-g the blank to rest upon atable or support 60 and beneath a suitable forming plate 6|, beyond which projects the blanks back portion 2. Cooperating with the forming plate 6| are a pair of folding devices 62, 62 (only one being shown), the latas described in the aforesaid Novick patent (see Fig. 4 of Novick) to fold the side flaps 3, 3 inwardlyl over the edges of said forming plate (see i, Fig. 9); after this, an oscillatory drum 63, carrying rotating rollers 64 and 65, move clockwise to engage the blank portion 2 from beneath and to refold it, on line I6, over the forward edge of plate 6|. The fold |6 is thus seized between the rollers 64 and 65, whose rotation strips or withdraws the blank from plate 6|, producing at the same time the requisite pressure to rmly stick the back portion 2 to the glue-coated side aps 3, 3. As the drum 63 makes its return or counterclockwise swing to the position shown in Fig. 2, the thus-formed envelope (see y', Fig. 9) folded except for its seal flap 5, is projected by the rollers 64 and 65 into other cooperating rollers 66, 66 which feed it, fold I6 foremost, onto belts 61. Here, as brought to rest beneath a forming plate 68 by a suitable stop 69, the operation of folding down the seal flap 5 is performed; for this purpose, an oscillatory drum 18, carrying rotating rollers 1| and 12, operates in the same way as drum 63 to fold theseal flap 5 over the edge of plate 66, after which the fold 13 thus formed (see i, Fig. 9) is seized by said rollers which, on the clockwise or return swing of drum 10, project the completed envelope, fold 13 foremost, into a chute 14 delivering to any suitable stacking and counting mechanism 15 (see m, Fig. 9)'.

Fig. 8 illustrates a somewhat different apparatus from that shown in Figs. 2, 6 and 'l for applying the` dry-adhesive substance in liquid form to the adjacent portions 4 and 5 of each lowermost partly-folded blank in the vvertical stack or pile. Said vertical stack or pile is formed and maintained in the same way, but the application of the coating solution to the desired areas is in this case effected by spraying-the solution being supplied froma suitable container 16 to a receptacle 11, from which latter leads a. tube 18 that delivers the solution in a regulated amount in the path of a jet of compressed air, supplied, for example, by a pipe 19. The air atomizes the solution and the mixture is discharged through a suitable nozzle 88 against the underneath surfaces or portions 4 and 5 of each lowermost blank,the confinement of the sprayed mixture to such areas being accomplished by segregating them by means, for example, of a partition 8|, from the remainder of the blank. Said partition 8| is preferably part of a casing 82 which surrounds the nozzle 80, being ar'- ranged to catch any drip or excess of the sprayedter operating,

on coating liquid. In this case, the withdrawal of each lowermost partly-folded blank from the vertical pile or stack is effected as before by a rotating Vsuction segment 30, cooperating with belts 21, 21 to engage the extended side flaps 3, 3 of each blank.

I claim:

1. In the manufacture of envelopes of the type adapted to lbe sealed by the contact of two complemental areas of dry-sealing adhesive, one area on the closure flap and the other on the envelopes rear wall, the improvement which consists in procuring for each envelope or blank in process the adjacent disposition of .the two areas destined to be coated 4with such adhesive, and subjecting each such envelope or blank separately to a single application of such adhesive in solution, for the coating of s'aid two areas.

2. In the manufacture of envelopes of the type adapted to be sealed by the contact of two complemental areas of dry-sealing adhesive, the improvement which consists in so folding each endrawing the blank from one end with each deliv- Velope blank as to dispose contiguous to each other the two blank areas destined to be coated with such adhesive, subjecting each so-folded blank separately to a single application of such adhesive in solution, for the coating of said two areas, simultaneously drying said adhesive-coated areas of each blank, and thereafter subjecting each blank to the gumming and folding operations required for its conversion into an envelope.

3. In a machine for making envelopes of the type adapted to be sealed by the contact of two complemental areas of dry-sealing adhesive, means for so folding each envelope blank as to dispose contiguous to each other'the two areas destined to be coated with such adhesive, and means for subjecting each so-folded blank separately to a single application of such adhesive in solution, for the coating of said two areas.

4. A machine for making envelopes of the type adapted to be sealed by the contact of two complemental areas of dry-sealing adhesive, comprising means for so folding each envelope blank as to dispose contiguous to each other the two areas destined to be coated with such adhesive, means for subjecting each so-folded blank separately to a single application of. such adhesive in solution, for the coating of said two areas, means for simultaneously drying said adhesive-coated areas of each blank, and means for thereafter subjecting each blank to the gumming and folding operations required for its conversion into an envelope.

5. In the manufacture of envelopes of the type adapted to be sealed by the contact of two complemental areas of dry-sealing adhesive, the improvement which consists in so folding each envelope blank as to dispose contiguous to each other the two blank areas destined to be coated with adhesive, forming a stack of the so-folded blanks, and procuring by the withdrawal of each such blank from said stack the coating of its two said areas with such adhesive in solution.

6. In the manufacture of envelopes f the type adapted to be sealed by the contact of two complemental areas of dry-sealing adhesive, the improvement which consists in'so folding each envelope blank as to dispose contiguous to each other the two blank areas destined to be coated with such adhesive, deliveringV each so-folded blank to one end of a stack of said blanks while withdrawing a blank from the other end of said stack, and by such withdrawal procuring the application of such adhesive in solution to the two said areas of the blank being withdrawn.

7. In a machine for making envelopes of the type adapted to be sealed by the contact of two complemental areas of dry-sealing adhesive, means for so folding each blank as to dispose contiguous to each other the two areas destined to be coatedwith such adhesive, means for forming a stack of the so-folded blanks, and means operative by successive withdrawals of said blanks from thel bottom of said stack for coating with such adhesive the two said areas of each blank so withdrawn.

8. In a machine for making envelopes of the type adapted to be sealed by the contact of two complemental areas of dry-sealing adhesive, means for so folding each envelope as to dispose contiguous to each other the two areas destined to be coated with such adhesive, means for stacking the so-folded blanks, and for maintaining such stack at substantially constant size by withery of the blank to the other end, means operative on each such .blank withdrawal for coating with the adhesive in solution the two said areas of the blank so withdrawn, means for simultaneously drying said adhesive-coated areas of each blank, and means for thereafter subjecting each blank to the gumming and folding operations required for its conversion into an envelope.

9. In the manufacture of envelopes of the type adapted to be sealed by the contact of 'two'com- 'plemcntal areas of dry-sealing adhesive, the improvement which consists in imparting an outward curl or warp to a margin of one of said arcas of each blank, so folding each Ablank as to dispose the so-curled area in adjacent relation to the other area, subjecting each. so-folded blank separately to a single application'of such adhesive in solution, for the coating of said two areas, and drying each blank in its partly-folded condition, the aforesaid warp or curl preventing said areas from sticking together during such drying.

10. In the manufacture of envelopes of the type adapted to be sealed by the contact ofv two complemental areas of dry-sealing adhesive, one area on the closure flap and the other on the envelopes rear wall, the improvement which consists in producing in each envelope or blank the adjacent disposition of the two areas destined to be coated with such adhesive, and by a separate operation on each envelope or blank procuring the coating of its said two areas with such adhesive.

11. In the manufacture of envelopes of the type adapted to be sealed by the contact of two complemental areas of dry-sealing adhesive, one area on the closure flap and the other on the envelopes rear wall, the improvement which consists in disposing adjacent to each other the two said areas of each blank, and applying to each blank separately an adhesive coating to cover said two areas.

12. In a machine for making envelopes of the type adapted to be sealed by the contact of two complemental areas of ydry-sealing adhesive, means for feeding the envelope blanks, meansoperative on each blank to dispose adjacent each other the said two areas, and means for applying to each blank individually an adhesive coating to cover its said two areas.

13. For envelopes adapted to be sealed by contact of two complemental dry-sealing adhesive areas, one on a closure flap and the other on a rear wall flap, both flaps, for the packing of such envelopes, being folded downI to prevent exposure of said areas, the improvement in manufacture which consists in procuring for each blank or envelope in process thedisposition alongside each other of its said two flaps in unfolded condition, and applying said dry-sealing adhesive to both naps by a separate operation on each envelope or blank.

14. In a machine for making envelopes of the type adapted to be sealed by the contact of two complemental areas of dry-sealing adhesive, the combination with stacking meachanism receiving the blanks of such envelopes in a folded condition that disposes alongside each other the two areas of each blank destined to be coated with such adhesive, of means operable at the bottom of said stacking mechanism for applying such adhesive simultaneously to the said two areas of each blank asthe latter, by successive withdrawals of the lowermost blank of the stack, arrives in position to be acted on by said adhesive-applying means.

15. In a machine for making envelope/s of the type adapted to be sealed by the contact oi two complemental areas of dry-sealing adhesive, the

combination with stacking mechanism receiving 2,1es,oss

sively to the gumming and folding operations required for their conversion into envelopes.

16. In apparatus for the manufacture of envelopes and like articles adapted to be sealed by the contact of two ilap and body areas ooated with drysealing adhesive, the combination with an applicator for such adhesive, said applicator being in substantial registry lengthwise with one of said areas of an envelope, of means for arranging said two areas of each envelope in sideby-side juxtaposed relation and means for moving each so-arranged envelope past said applicator with itsother areas shielded from contact therewith, thereby to obtain at each movement the adhesive coatings of both o! said ilrst' mentioned areas.

- VINCENT E. HYWOOD. 

